Changes in Glutamatergic Neurotransmission of Severe TBI Patients
Public ClinicalTrials.gov record NCT04244058. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
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Official title
Evaluation of Pharmacologically-induced Changes in Excitatory Glutamatergic Neurotransmission of Severe TBI Patients
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Studies in patients with disorders of consciousness (DOC) after severe brain injury implicate dysfunction of the anterior forebrain mesocircuit dysfunction a key underlying mechanism. The anterior forebrain metabolism in DOC is markedly downregulated across brain regions underpinning highly elaborated cognitive behaviors demonstrating a collapse of the level of synaptic background activity required for consistent goal-directed behavior and arousal regulation. Since dopamine levels are one of the primary controllers of the level of synaptic background activity within these forebrain structures and in regulating excitatory glutamatergic homeostasis, the investigators propose to investigate the specific contribution of presynaptic dopamine function in glutamatergic neurotransmission in posttraumatic DOC. The aim of the present study is to measure metabotropic glutamate receptors 5 occupancy in the main gutamatergic structures of the brain using (3-\[18F\]fluoro-5-(2-pyridinylethynyl)benzonitrile)-positron emission tomography ( \[18F\]FPEB-PET) at rest and following a short pharmacological challenge with amantadine, an N-methyl-D-aspartate receptor (NMDA-R) antagonist, following L-DOPA, and amantadine + L-DOPA. Using this novel technique in DOC the investigators will characterize the relevance of a presynaptic deficiency to synthesize and/or release dopamine in the final regulation of excitatory interneurons of the anterior forebrain mesocircuit. It is unknown whether glutamatergic neurotransmission is affected across the population of subjects with DOC and, if this condition is secondary to a presynaptic dopaminergic failure of the anterior forebrain mesocircuit (i.e., down-regulation). Since the investigators previously identified the existence of a presynaptic dopaminergic deficit in these subjects due to a failure in the biosynthesis of dopamine, the investigators will evaluate if by providing the main biological substrate of the biosynthesis process (i.e., L-DOPA) the glutamatergic system regains homeostasis. The investigators therefore propose to investigate patients with posttraumatic DOC using \[18F\]FPEB-PET at rest and following short pharmacological challenges aimed at increasing glutamate and dopamine release.
Study identification
- NCT ID
- NCT04244058
- Recruitment status
- Suspended
- Study type
- Interventional
- Phase
- Early Phase 1
- Enrollment
- 30 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 18 Years to 75 Years
- Sex
- All
- Healthy volunteers
- Accepts healthy volunteers
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Sep 22, 2020
- Primary completion
- May 29, 2023
- Completion
- Jun 29, 2023
- Last update posted
- Sep 29, 2022
2020 – 2023
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Weill Cornell Medicine | New York | New York | 10065 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04244058, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Sep 29, 2022 · Synced Sep 1, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT04244058 live on ClinicalTrials.gov.